1. Field of the Invention
The present invention relates to a capsule endoscope activation system which applies a magnetic field to a reed switch disposed inside a capsule endoscope to switch a driving state of the capsule endoscope from an off state to an on state.
2. Description of the Related Art
In recent years, swallowable type capsule endoscopes have been proposed in the field of an endoscope. This capsule endoscope is provided with an imaging function and a wireless communication function. The capsule endoscope has a function of, after the capsule endoscope is swallowed from a mouth of a subject (human body) for observation (examination), moving inside the body cavity such as the interior of an organ such as the stomach or small intestine according to peristaltic motions and sequentially capturing images until the capsule endoscope is spontaneously excreted.
Image data captured inside the body by the capsule endoscope while the capsule endoscope moves in the body cavity is sequentially transmitted to the outside by radio transmission and accumulated in memory provided outside. If the subject carries a receiving device which has a wireless communication function and a memory function, after swallowing the capsule endoscope, the subject can go where the subject likes until the endoscope is excreted. After the capsule endoscope is excreted, a doctor or nurse can make diagnosis by displaying images of organs on a display based on image data accumulated in the memory.
With this capsule endoscope, a reed switch which functions in response to a magnetic field applied from an outside is used to supply power from a power source to each function executing unit. Generally, with an existing reed switch, two magnetic reeds are arranged at a predetermined interval facing each other, and attract and contact each other when the magnetic field is applied in an axial direction of the reeds from an outside so as to electrically conduct between circuits. Further, by contrast with this, when the magnetic field is applied in the axial direction of the reeds from the outside, the reeds are separated, thereby releasing between circuits, and can electrically conduct between the circuits when the magnetic field is not applied. Hence, to switch between on and off of a power source using this reed switch, it is necessary to match a magnetic field direction and an axial direction of the reeds of the reed switch.
To realize the capsule endoscope having the above switch, for example, Japanese Laid-open Patent Publication No. 2005-95433 proposes a configuration where a capsule endoscope which has inside a reed switch which is turned on and off in response to an external magnetic field to control driving of the capsule endoscope is housed in a capsule container including a permanent magnetic which produces this external magnetic field. That is, the reed switch provided in the capsule endoscope adopts a structure which maintains the off state under environment in which the magnetic field of a certain intensity or more is applied, and is turned on when the intensity of the external magnetic field goes below a predetermined intensity. Therefore, in a state where the capsule endoscope is housed in the capsule container, the capsule endoscope is not driven. Further, by taking this capsule endoscope out of the capsule container upon swallowing, the capsule endoscope is spaced apart from the permanent magnet and is no longer influenced by the magnetism, and starts being driven.